Combinations of crop protection agents with anionic polymers

ABSTRACT

The present invention relates to a combination of a cationic agrochemically active compound with an anionic polymer having negatively charged functional groups, with formation of electrostatic interactions for the controlled release of this active compound. This combination permits the suppression of antagonistic interactions of various active compounds with one another, and also better crop selectivity.

[0001] The present invention relates to combinations of crop protectionagents with polymeric anionic auxiliaries which permit a controlledrelease of an active compound. The combinations can be used to increasecrop selectivities and to reduce antagonisms and give particularly goodresults in the case of herbicides, in particular in the case of mixturesof herbicides with growth regulators and safeners.

[0002] It is known that various application problems, reduced activityowing to antagonistic interactions between two or more active compoundsand insufficient so-called crop compatibility and associated undesirabledamage to the plants can occur during the application of variousagrochemical products, for example herbicides, fungicides, insecticides,plant growth regulators, safeners or fertilizers. It is furthermoreknown that these phenomena are frequently observed during so-calledfoliar application, and again in particular in the case of herbicides orelse of mixtures of herbicides with safeners and/or growth regulators.

[0003] To avoid these problems, a so-called split application, forexample, or an overdosage of the active compound that is antagonized hasbeen recommended for cases of reduced activity owing to antagonism. Incases of poor selectivity or insufficient crop compatibility, it isoften likewise possible to use split application; an alternative optionis underdosage. However, for various reasons, all of these proceduresare rather unattractive and uneconomical. When using split application,the active compound formulation has to be applied at least twice; thisis time-consuming and labor-intensive. Overdosage of an active compoundresults in additional expenditure, underdosage involves the risk ofreduced yields owing to insufficient control of harmful organisms.

[0004] U.S. Pat. No. 5,428,000 discloses active compound compositionscomprising a herbicide for broad-leaved weeds and a herbicide for weedgrasses. The herbicide for weed grasses has a neutral charge; incontrast, the herbicide for broad-leaved weeds is of anionic nature andis present in combination with a hydrophilic polymer, the polymer beinga copolymer formed from an ammonium-containing compound and a compoundwhich does not contain any ammonium. The ammonium-containing compound isgenerally derived from aromatic and nonaromatic nitrogen heterocycles,ammonium derivatives of acrylic acid and benzylammonium compounds. Thus,the polymers are exclusively polymers in which the quaternary nitrogenatom is not contained in the main chain of the polymer. The hydrophilicpolymers used are exclusively copolymers of the abovementioned type. Theherbicides for weed grasses used are sethoxydim, alloxidim, fluazifop,quizalofop or fenoxaprop; for broad-leaved weeds, the use of bentazone,imazaquin, acifluorfen, fomesafen, chlorimuron, imazethapyr,thifensulfuron and 2,4-D has been described.

[0005] DE 198 33 066 discloses aqueous dispersions of polymers withcationic functionality and redispersible powders obtainable from thedispersions, and also their use, inter alia for the delayed release ofactive compounds of any kind.

[0006] It is an object of the present invention to provide formulationsof crop protection agents which render the requirement of splitapplications and overdosage or underdosage obsolete.

[0007] This object is achieved by a combination of at least oneagrochemically active compound having cationic functional groups, inparticular a herbicide, with a anionic polymer with formation ofelectrostatic interaction between these components for the controlledrelease of this active compound.

[0008] It has been found that problems such as poor selectivity andinsufficient crop compatibility or reduced activity caused by antagonismcan be avoided by combining certain anionic polymers with one or moreagrochemically active compounds.

[0009] The present invention furthermore provides the application of thecombination according to the invention for controlling undesirableharmful organisms, in particular undesirable grasses and broad-leavedweeds.

[0010] In the present invention, the term “polymer” includes botholigomers and polymers and also homo- and copolymers or -oligomers ofthe corresponding monomers, i.e. molecules having a low degree ofpolymerization and also those having a high degree of polymerization.The molecular weights M_(N) of the compounds which can be used accordingto the invention as polymers are at least 500.

[0011] In the polymer/active compound combination according to theinvention, some or all of the agrochemically active compound enters intoan attractive reversible intermolecular interaction with the oligomer orpolymer. These interactions are electrostatic interactions. Theagrochemically active compound can be an active compound having partialselectivity. Alternatively, it is also possible for an active compoundwhich, in an intended active compound mixture, shows antagonisticaction, to interact with the polymer. It is also possible for two ormore active compounds in an active compound mixture to enter into suchan interaction.

[0012] The anionic polymers used according to the invention can also besurface-active molecules. Owing to their physicochemical properties,they can be dispersed, emulsified or dissolved in water and/or organicsolvents. The polymers are preferably dissolved, the preferred solventsbeing polar protic and polar aprotic organic solvents and water. Mostpreferably, the polymers dissolve in water.

[0013] Polymers suitable for the combinations according to the inventionpreferably penetrate only slowly, if at all, into the harmful organism,penetration generally taking place, for example, via the leaf or theroot. In general, the absorption rate or penetration rate of thepolymers used according to the invention is between<0.01% and 80%,preferably considerably less than 50%, in 24 hours.

[0014] The polymers used according to the invention have negativelycharged functional groups. In general, the mean molecular weight M_(N)of the polymers used according to the invention is≧500, preferably fromabout 1 000 to 1 000 000. These polymers in question can be homo- orcopolymers and are produced in customary polymerization reactions, forexample polyadditions, polycondensations, free-radical and ionicpolymerizations and metal-complex-catalyzed polymerizations. Alsosuitable are modified or unmodified natural polymers, for example oligo-and polypeptides and oligo- and polysaccharides.

[0015] Suitable negatively charged functional groups are carboxylate(COO^(⊖)), sulfonate (SO₃ ^(⊖)), sulfate (OSO₃ ^(⊖)), phosphonate(P(O)O₂ ²⁻, P(O)ORO^(⊖)) and phospate groups (OP(O)O₂ ^(2⊖),OP(O)ORO^(⊖)).

[0016] Suitable polymers which may contain the abovementioned functionalgroups are polymers of organic nature, for example lignins and polymersbased on allyl, (meth)acryl and vinyl monomers and polymers of inorganicnature, for example silicates.

[0017] Examples of preferred polymers include sulfonized and sulfatizedlignin, polyacrylates, polymethacrylates, polyvinyl acetate,polycarbonates, polyesters, polyaspartates, phospholipids andpolysaccharides.

[0018] Further suitable anionic polymers are known to the person skilledin the art. In general, commercial products will be employed.

[0019] Agrochemically active compounds which are suitable for thepresent invention have functional groups which are positively charged orcarry a positive partial charge and can be converted into cationicfunctions. It is also possible for the active compounds to be present ascations even before formulation. However, it is also possible that theseactive compounds are converted into cations only during the formulationor the preparation of the so-called tank mix, for example by protonationor by abstraction of groups or counterions during these processes.

[0020] Cationic active compounds suitable for use in the combinationsaccording to the invention are those which belong to the group of theherbicides, fungicides, insecticides, growth regulators, safeners,acaricides, molluscicides and nematicides.

[0021] Particularly suitable for combination with the polymerscontaining anionic functions are herbicides, among these in particularglufosinate, glyphosate, paraquat, diquat, difenzoquat, metilsulfat,mepiquat, chlormequat and bialaphos. The abovementioned active compoundscan, if appropriate, be present in the form of the derivatives known tothe person skilled in the art, such as salts, for example in thecustomary known quaternized form, which is shown in the literature onthe subject, such as, for example, in “The Pesticide Manual”, C D STomlin Ed., British Crop Protection Council, Farnham (GB), 1997.

[0022] The combinations according to the invention permit the phytotoxicpotential of active compounds to be reduced and antagonization of otheractive compounds in mixtures with the former to be suppressed. Activecompounds to be combined according to the invention can therefore beused together with other active compounds or as sole active compound, ifappropriate together with customary additives and adjuvants. Examples ofpreferred combinations according to the invention are described below.In all these combinations, the use of the active compounds describedabove as being particularly suitable or most suitable is, of course,likewise preferred, even if this is not explicitly mentioned.

[0023] The agrochemically active compounds combined with the polymersused according to the invention can be formulated with other activecompounds which, if appropriate, are likewise combined with polymersaccording to the present invention, to afford mixtures givingadvantageous results.

[0024] A preferred embodiment of the present invention are combinationsin which some or all of an agrochemically active compound, for example aherbicide, is combined according to the invention with an anionicpolymer, the combination additionally comprising at least one furtheragrochemically active compound, for example a herbicide or safener.

[0025] In a further preferred embodiment of the present invention,herbicides with safeners and/or growth regulators are formulated incombination with the polymers used according to the invention, where atleast one of the agrochemically active compounds has been combinedaccording to the invention with these polymers.

[0026] It is furthermore preferred to combine one or more herbicideshaving a rapid mechanism of action with one or more herbicides having arelatively slow mechanism of action, where at least one of theagrochemically active compounds has been combined according to theinvention.

[0027] Further preferred embodiments are herbicidal mixtures comprisingthe combination glufosinate/paraquat, glufosinate/diquat,glyphosate/paraquat or glyphosate/diquat, where at least one of theagrochemically active compounds has been combined according to theinvention.

[0028] In a further preferred embodiment, one or more graminicides aremixed with a safener and optionally a plant growth regulator, where atleast one of the agrochemically active compounds has been combinedaccording to the invention.

[0029] In the combinations according to the invention, the weight ratioof polymer to cationic active compound or compounds is, depending on themolecular weight of the monomer and the active compound and on otherphysicochemical parameters known to the person skilled in the art, from0.001:1 to 1:0.001, preferably from 0.01:1 to 1:0.01, most preferablyfrom 0.1:1 to 1:0.1.

[0030] In many cases, it is advantageous to add adjuvants, for exampleoils, special solvents, surfactants or surfactant mixtures. Here,adjuvants are to be understood as meaning those additives to activecompound/polymer combinations which are not active themselves butenhance the properties of the active compound. Suitable adjuvants arenonionic surfactants, for example those of the formula RO(CH₂CH₂O)_(n)H,in which R is a (C₁₀-C₂₂)-fatty alcohol radical, a tristyrylphenolradical, a butylphenol radical, a (C₁-C₁₄)-alkylphenol radical, atridecyl alcohol radical, a glyceride radical or a radical derived fromcastor oil and n is an integer of from 1 to 500, preferably from 3 to200.

[0031] Such substances are obtainable, for example, as Genapol®,Sapogenat® and Arkopal® series from Clariant GmbH and as Soprophor®series from Rhodia GmbH. It is also possible to employ block copolymersbased on ethylene oxide, propylene oxide and/or butylene oxide, forexample the compounds sold by BASF AG under the names Pluronics® orTetronics®.

[0032] Anionic or betainic surfactants, too, can be used. Examples ofanionic surfactants include calcium dodecylbenzylsulfonate, succinates,phosphated, sulfated and sulfonated nonionic surfactants, for examplethose of the type mentioned above, and sorbitates, these anioniccompounds being neutralized with alkali metal, alkaline earth metal orammonium ions. Such surfactants are available, for example, under thename Genapol® LRO (Clariant GmbH).

[0033] Betainic surfactants are obtainable, for example, fromGoldschmidt AG under the name Tegotain®.

[0034] Also suitable are cationic surfactants, for example those basedon quaternary ammonium, phosphonium and tertiary sulfonium salts, forexample Atlas® G3634 A from Uniquema.

[0035] The amount of surfactant used is from 10 to 2 000 g/ha,preferably from 50 to 2 000 g/ha. The addition of nitrogen, for examplein the form of urea, ammonium nitrate, ammonium sulfate, ammoniumhydrogen sulfate or mixtures thereof, is likewise often advantageous.

[0036] Formulations comprising combinations according to the inventionare described in an exemplary manner below.

[0037] It is possible to use glufosinate (250-500 g/ha) with paraquat(10-400 g/ha) together with polyacrylates (1-500 g/ha) to increase thetotal herbicidal action compared to a combination of the two activecompounds without a suitable polymer.

[0038] To prevent a reduced action owing to antagonistic interactions,it is possible to combine mixtures of glufosinates with diquat orparaquat with known polymers of the Geropon® type from Rhodia GmbH or ofthe Reax® type from Westvaco.

[0039] Further substances which may optionally be present are safeners,other herbicides, adjuvants such as, for example, Genapol® LRO orfertilizers such as, for example, ammonium sulfate, ammonium hydrogensulfate, urea or ammonium nitrate.

[0040] To prevent a reduced action owing to antagonistic interactions,it is possible to combine mixtures of glyphosates with diquat orparaquat with known polymers of the Geropon® type from Rhodia GmbH or ofthe Reax® type from Westvaco. Further substances which may optionally bepresent are safeners, other herbicides, adjuvants such as, for example,Genapol® LRO or fertilizers such as, for example, ammonium sulfate,ammonium hydrogen sulfate, urea or ammonium nitrate.

[0041] The percentage of the active compounds in the variousformulations can be varied within wide ranges. The formulationscomprise, for example, from about 0.1 to 95% by weight of activecompounds, about 90-10% by weight of liquid or solid carriers and, ifappropriate, up to 50% by weight, preferably up to 30% by weight, ofsurfactants, where the sum of these percentages should be 100%.

[0042] The mixtures, prepared according to the invention, of polymer,one or more active compounds and optional adjuvants and otherauxiliaries can also be present as a separate tank mix, and also inother formulatons.

[0043] Suitable possible formulations are, for example:

[0044] wettable powders (WP), water-soluble powders (SP), suspensionconcentrates (SC) based on oil or water, water-soluble concentrates(SL), emulsifiable concentrates (EC), micro- and macroemulsions (EW/ME),such as oil-in-water and water-in-oil emulsions, sprayable solutions,suspension emulsions (SE), oil-miscible solutions, capsule suspensions(CS), dusts (DP), seed-dressing compositions, granules for broadcastingand soil application, granules (GR) in the form of microgranules, spraygranules, coating granules and adsorption granules, water-dispersiblegranules (WDG), water-soluble granules (WSG), ULV formulations,microcapsules and waxes. These individual formulation types are known inprinciple and are described, for example, in Winnacker-Küchler,“Chemische Technologie” [Chemical Technology], Volume 7, C. HanserVerlag Munich, 4th Edition, 1986; Wade van Valkenburg, “PesticideFormulations”, Marcel Dekker, N.Y., 1973; K. Martens, “Spray Drying”Handbook, 3^(rd) Ed. 1979, G. Goodwin Ltd. London.

[0045] Formulation auxiliaries, such as inert materials, surfactants,solvents and other additives, are likewise known and are described, forexample, in Watkins, “Handbook of Insecticide Dust Diluents andCarriers”, 2^(nd) Ed., Darland Books, Caldwell N.J., H. v. Olphen,“Introduction to Clay Colloid Chemistry”, 2^(nd) Ed., J. Wiley & Sons,N.Y.; C. Marsden, “Solvents Guide”, 2^(nd) Ed., Interscience, N.Y. 1963;McCutcheon's “Detergents and Emulsifiers Annual”, MC Publ. Corp.,Ridgewood N.J.; Sisley and Wood, “Encyclopedia of Surface ActiveAgents”, Chem. Publ. Co. Inc., N.Y. 1964; Schönfeldt,“Grenzflächenaktive Äthylenoxidaddukte [Surface-Active Ethylene OxideAdducts]”, Wiss. Verlagsgesell., Stuttgart 1976; Winnacker-Küchler,“Chemische Technologie”, Volume 7, C. Hanser Verlag Munich, 4th Edition1986.

[0046] Wettable powders are preparations which are uniformly dispersiblein water and which contain, in addition to the combination according tothe invention and as well as a diluent or inert substance, surfactantsof ionic and/or nonionic nature (wetting agents, dispersants), forexample polyethoxylated alkylphenols, polyethoxylated fatty alcohols,polyethoxylated fatty amines, fatty alcohol polyglycol ether sulfates,alkanesulfonates, alkylbenzenesulfonates, sodium lignosulfonate, sodium2,2′-dinaphthylmethane-6,6′-disulfonate, sodiumdibutyinaphthalenesulfonate or else sodium oleoylmethyltaurinate. Toprepare the wettable powders, the active compounds are finely ground incustomary apparatus such as hammer mills, fan mills or air-jet mills,and are mixed simultaneously or subsequently with the formulationauxiliaries and also the polymers used according to the invention.

[0047] Emulsifiable concentrates are prepared by dissolving the activecompounds in combination with the polymer in an organic solvent, forexample butanol, cyclohexanone, dimethylformamide, xylene or elserelatively high-boiling aromatic compounds or hydrocarbons or mixturesof the organic solvents, with the addition of one or more surfactants ofionic and/or nonionic nature (emulsifiers). Examples of emulsifierswhich can be used are calcium alkylarylsulfonates, such as calciumdodecylbenzenesulfonate, or nonionic emulsifiers, such as alkylarylpolyglycol ethers different from para-alkylphenol ethoxylates, fattyacid polyglycol esters, fatty alcohol polyglycol ethers, propyleneoxide-ethylene oxide condensation products, alkyl polyethers, sorbitanesters, for example sorbitan fatty acid esters, or polyoxyethylenesorbitan esters, for example polyoxyethylene sorbitan fatty acid esters.

[0048] Dusts are obtained by grinding the active compound in combinationwith polymers to be used according to the invention with finely dividedsolid substances, for example, talc, natural clays, such as kaolin,bentonite and pyrophillite, or diatomaceous earth.

[0049] Suspension concentrates can be water- or oil-based. They can beprepared, for example, by wet milling using commercially customary beadmills, with or without the addition of surfactants as already mentionedabove under the other formulation types.

[0050] Emulsions, for example oil-in-water emulsions (EW), can beprepared, for example, by means of stirrers, colloid mills and/or staticmixers using aqueous organic solvents and, if desired, surfactants, forexample as already mentioned above under the other formulation types.

[0051] Granules can be prepared either by spraying the active compoundin combination with the polymer to be used according to the inventiononto adsorptive, granulated inert material or by applying thecombination to the surface of carriers, such as sand, kaolinites or ofgranulated inert material, by means of adhesives, for example sugars,such as pentoses and hexoses and also mineral oils. Suitable activecompounds in combination with the polymer to be used according to theinvention can also be granulated in the manner which is customary forthe preparation of fertilizer granules, if desired as a mixture withfertilizers.

[0052] Water-dispersible granules are generally prepared by thecustomary processes, such as spray-drying, fluidized-bed granulation,disk granulation, mixing using high-speed mixers, and extrusion withoutsolid inert material.

[0053] For the preparation of disk, fluidized-bed, extruder and spraygranules, see, for example, the processes in “Spray-Drying Handbook”3^(rd) Ed. 1979, G. Goodwin Ltd., London; J. E. Browning,“Agglomeration”, Chemical and Engineering 1967, pages 147 ff.; “Perry'sChemical Engineer's Handbook”, 5^(th) Ed., McGraw-Hill, New York 1973,pp. 8-57.

[0054] For further details on the formulation of crop protectionproducts, see, for example, G. C. Klingman, “Weed Control as a Science”,John Wiley and Sons, Inc., New York, 1961, pages 81-96 and J. D. Freyer,S. A. Evans, “Weed Control Handbook”, 5^(th) Ed., Blackwell ScientificPublications, Oxford, 1968, pages 101-103.

[0055] In addition, said formulations of the combinations according tothe invention may comprise the tackifiers, wetting agents, dispersants,emulsifiers, penetrants, preservatives, antifreeze agents, solvents,fillers, carriers, colorants, antifoams, evaporation inhibitors and pHand viscosity regulators which are customary in each case.

[0056] Based on these formulations, it is also possible to preparemixtures with other pesticidally active compounds, such as herbicides,insecticides, fungicides, and also antidotes or safeners, fertilizersand/or growth regulators, for example in the form of a finishedformulation or for use as tank mixes.

[0057] The combinations according to the invention have outstandingactivity. If herbicides are combined with polymers to give thecombinations according to the invention, the combinations have excellentherbicidal activity against a broad spectrum of economically importantmonocotyledonous and dicotyledonous harmful plants. The active compoundcombinations also act efficiently on perennial weeds which produceshoots from seeds or rhizomes, root stocks or other perennial organs andwhich are difficult to control. In this context, it is immaterialwhether the combinations according to the invention are appliedpre-sowing, pre-emergence or post-emergence. The combinations accordingto the invention are preferably applied onto above-ground parts ofplants. The combinations according to the invention are also suitablefor dessicating crop plants such as potato, cotton and sunflower.

[0058] In the case of herbicidally active compounds, the combinationsaccording to the invention can be used, for example, for controlling thefollowing harmful plants:

[0059] Dicotyledonous weeds of the genera Sinapis, Galium, Stellaria,Matricaria, Galinsoga, Chenopodium, Brassica, Urtica, Senecio,Amaranthus, Portulaca, Xanthium, Convolvulus, Ipomoea, Polygonum,Sesbania, Cirsium, Carduus, Sonchus, Solanum, Lamium, Veronica,Abutilon, Datura, Viola, Monochoria, Commalina, Sphenoclea,Aeschynomene, Heteranthera, Papaver, Euphorbia and Bidens.

[0060] Monocotyledonous weeds of the genera Avena, Alopecurus,Echinochloa, Setaria, Panicum, Digitaria, Poa, Eleusine, Brachiaria,Lolium, Bromus, Cyperus, Elytrigia, Sorphum, Apera and Scirpus.

[0061] If the herbicidal compositions which comprise the combinationsaccording to the invention are applied prior to germination, then theweed seedlings are either prevented completely from emerging, or theweeds grow until they have reached the cotyledon stage but then theirgrowth stops, and, eventually, after three to four weeks have elapsed,they die completely.

[0062] If the herbicidal compositions which comprise the combinationsaccording to the invention are applied post-emergence to the green partsof the plants, growth also stops drastically a very short time after thetreatment and the weed plants remain at the development stage of thepoint in time of application, or they die completely after a certaintime, more or less rapidly, so that in this manner competition by theweeds, which is harmful to the crop plants, is eliminated at a veryearly point in time and in a sustained manner by employing the novelcombinations according to the invention, as are associated quantitativeand qualitative losses in yield.

[0063] Although these combinations according to the invention haveexcellent herbicidal activity against monocotyledonous anddicotyledonous weeds, damage to the crop plant is insignificant, ifthere is any damage at all.

[0064] These effects allow, inter alia, the application rate to bereduced, a broader spectrum of broad-leaved weeds and weed grasses to becontrolled, activity gaps to be closed, also with respect to resistantspecies, more rapid and safer action, longer duration of action,complete control of the harmful plants using only one or a fewapplications, and a prolonged application period if a plurality ofactive compounds are present at the same time.

[0065] The abovementioned properties are required for weed control inpractice to keep agricultural crops free of undesirable competing plantsand to safeguard and/or increase yield quality and quantity. Withrespect to the properties described, the combinations according to theinvention are considerably superior to the prior art. In addition, thecombinations according to the invention permit, in an excellent manner,the control of otherwise resistant harmful plants.

[0066] Owing to their agrochemical properties, preferably herbicidal,plant-growth-regulatory and safener properties, the combinationsaccording to the invention, which are preferably employed in herbicidalcompositions, can also be employed for controlling harmful plants incrops of known or still to be developed genetically engineered plants.The transgenic plants generally have particularly advantageousproperties, for example resistance to certain pesticides, in particularcertain herbicides, resistance to plant diseases or causative organismsof plant diseases, such as certain insects or microorganisms such asfungi, bacteria or viruses. Other particular properties relate, forexample, to the quantity, quality, storage-stability, composition and tospecific ingredients of the harvested product. Thus, transgenic plantshaving an increased starch content or a modified quality of the starchor those having a different fatty acid composition of the harvestedproduct are known.

[0067] The use of the combinations according to the invention ineconomically important transgenic crops of useful and ornamental plants,for example of cereal, such as wheat, barley, rye, oats, millet, rice,manioc and corn, or else in crops of sugar beet, cotton, soya, oilseedrape, potato, tomato, pea and other vegetable species is preferred.

[0068] The combinations according to the invention can preferably beused in herbicides in crops of useful plants which are resistant orwhich have been made resistant by genetic engineering toward thephytotoxic effects of the herbicides.

[0069] Conventional ways for preparing novel plants which have modifiedproperties compared to known plants comprise, for example, traditionalbreeding methods and the generation of mutants. Alternatively, novelplants having modified properties can be generated with the aid ofgenetic engineering methods (see, for example, EP-A-0 221 044, EP-A-0131 624). For example, there have been described several cases of

[0070] genetically engineered changes in crop plants in order to modifythe starch synthesized in the plants (for example WO 92/11376, WO92/14827, WO 91/19806),

[0071] transgenic crop plants which are resistant to certain herbicidesof the glufosinate (cf., for example, EP-A-0 242 236, EP-A-0 242 246) orglyphosate (WO 92/00377) or sulfonylurea (EP-A-0 257 993, U.S. Pat. No.5,013,659) type,

[0072] transgenic crop plants, for example cotton, having the ability toproduce Bacillius thuringiensis toxins (Bt toxins) which impart to theplants resistance to certain pests (EP-A-0 142 924, EP-A-0 193 259),

[0073] transgenic crop plants having a modified fatty acid composition(WO 91/13972).

[0074] Numerous molecular biological techniques which allow thepreparation of novel transgenic plants having modified properties areknown in principle; see, for example, Sambrook et al., MolecularCloning, A Laboratory Manual, 2nd Ed. Cold Spring Harbor LaboratoryPress, Cold Spring Harbor, N.Y., or Winnacker “Genes and Clones”, V C HWeinheim 2nd Edition 1996 or Christou, “Trends in Plant Science” 1(1996) 423-431.

[0075] In order to carry out such genetic engineering manipulations, itis possible to introduce nucleic acid molecules into plasmids whichallow a mutagenesis or a change in the sequence to occur byrecombination of DNA sequences. Using the abovementioned standardprocedures, it is possible, for example, to exchange bases, to removepartial sequences or to add natural or synthetic sequences. To link theDNA fragments to one another, it is possible to attach adapters orlinkers to the fragments.

[0076] Plant cells having a reduced activity of a gene product can beprepared, for example, by expressing at least one appropriateantisense-RNA, a sense-RNA to achieve a cosuppression effect, or byexpressing at least one appropriately constructed ribozyme whichspecifically cleaves transcripts of the abovementioned gene product.

[0077] To this end, it is possible to employ either DNA molecules whichcomprise the entire coding sequence of a gene product including anyflanking sequences that may be present, or DNA molecules which compriseonly parts of the coding sequence, it being necessary for these parts tobe long enough to cause an antisense effect in the cells. It is alsopossible to use DNA sequences which have a high degree of homology tothe coding sequences of a gene product but which are not entirelyidentical.

[0078] When expressing nucleic acid molecules in plants, the synthesizedprotein can be localized in any desired compartment of the plant cell.However, to achieve localization in a certain compartment, it is, forexample, possible to link the coding region with DNA sequences whichensure localization in a certain compartment. Such sequences are knownto the person skilled in the art (see, for example, Braun et al., EMBOJ. 11 (1992), 3219-3227; Wolter et al., Proc. Natl. Aca. Sci. USA 85(1988), 846-850; Sonnewald et al., Plant J. 1 (1991), 95-106).

[0079] The transgenic plant cells can be regenerated through wholeplants using known techniques. The transgenic plants can in principle beplants of any desired plant species, i.e. both monocotyledonous anddicotyledonous plants. In this manner, it is possible to obtaintransgenic plants which have modified properties by overexpression,suppresion or inhibition of homologous (=natural) genes or genesequences or by expression of heterologous (=foreign) genes or genesequences.

[0080] The combinations according to the invention can preferably beused in transgenic crops which are resistant to herbicides from thegroup consisting of the sulfonylureas, glufosinate-ammonium orglyphosate-isopropylammonium and analogous active compounds.

[0081] When using the combinations according to the invention, inparticular those in herbicidal compositions, in transgenic crops, inaddition to the effects against harmful plants which can be observed inother crops, there are frequently effects which are specific for theapplication in the respective transgenic crop, for example a modified orspecifically broadened spectrum of weeds which can be controlled;modified application rate which can be used for the application;preferably good miscibility or combinability with the herbicides towhich the transgenic crops are resistant; and an effect on the growthand the yield of the transgenic crop plants.

[0082] The invention is now additionally illustrated in the examplesbelow.

[0083] In all examples, seeds or rhizome pieces of mono- anddicotyledonous harmful plants and useful plants were placed in sandyloam soil in pots having a diameter of 9-13 cm and covered with soil.The pots were kept in a greenhouse under optimum conditions. In thetwo-leaf to three-leaf stage, i.e. about 3 weeks after start ofcultivation, the test plants were treated with the combinationsaccording to the invention in the form of aqueous dispersions orsuspensions or emulsions and sprayed onto the green parts of the plantat various dosages, using a water application rate of 300 l/ha(converter). For further cultivation of the plants, the pots were keptin a greenhouse under optimum conditions. Visual scoring of the damageto useful plants and crop plants was carried out 2-3 weeks after thetreatment.

EXAMPLE 1

[0084] A mixture of glufosinate (300 g/ha) and diquat (50 g/ha) wascombined with 30 g/ha of Geropon® T36 (from Rhodia GmbH) and, fordesiccation, applied to crops of potatoes and sunflowers and in aso-called Liberty Link crop such as corn. Compared to the application ofa mixture of glufosinate (300 g/ha) and diquat (50 g/ha), a considerablyincreased activity was observed.

EXAMPLE 2

[0085] A mixture of glufosinate (300 g/ha) and diquat (50 g/ha) wascombined with 60 g/ha of Geropon® T36 (from Rhodia GmbH) and, fordesiccation, applied to crops of potatoes and sunflowers and in aso-called Liberty Link crop such as corn. Compared to the application ofa mixture of glufosinate (300 g/ha) and diquat (50 g/ha), a considerablyincreased activity was observed.

EXAMPLE 3

[0086] A mixture of glufosinate (300 g/ha) and diquat (50 g/ha) wascombined with 90 g/ha of Geropon® T36 (from Rhodia GmbH) and, fordesiccation, applied to crops of potatoes and sunflowers and in aso-called Liberty Link crop such as corn. Compared to the application ofa mixture of glufosinate (300 g/ha) and diquat (50 g/ha), a considerablyincreased activity was observed.

1. A combination of at least one agrochemically active compound havingcationic functional groups with an anionic polymer with formation ofelectrostatic interactions between these components.
 2. The combinationas claimed in claim 1, wherein the active compound is selected from thegroup consisting of herbicides, fungicides, insecticides, growthregulators, safeners, acaricides, molluscicides and nematicides, inparticular from the group consisting of herbicides, safeners and plantgrowth regulators.
 3. The combination as claimed in claim 2, wherein theherbicides are selected from the group consisting of glufosinate,glyphosate, paraquat, diquat, difenzoquat, metilsulfat, mepiquat,chlormequat and bialaphos and also quaternized forms, which are knownper se, of these active compounds.
 4. The combination as claimed inclaim 3, wherein the polymer is soluble, dispersible and/or emulsifiablein water and/or organic solvents, preferably in polar protic and/orpolar aprotic organic solvents and/or water, most preferably in water,and has an absorption rate or penetration rate of<50% in 24 h.
 5. Thecombination as claimed in claim 1, wherein the molecular weight M_(N) Ofthe polymer is>500, preferably about 1 000 to 1 000 000, and the polymeris employed in a weight ratio to the active compound of from about0.001:1 to about 1:0.001, preferably from 0.01:1 to 1:0.01, mostpreferably from 0.1:1 to 1:0.1.
 6. The combination as claimed in claim1, wherein the polymer has functional groups selected from carboxylate,sulfonate, sulfate or phosphonate groups, preferably from the groupconsisting of polyacrylates, polymethacrylates, sulfonated lignin,sulfated lignin, polyvinyl acetate, polycarbonates, polyesters,polyaspartates, phospholipids, polysaccharides and silicates.
 7. Aformulation, comprising a combination as claimed in claim 1 and at leastone further component from the group consisting of furtheragrochemically active compounds, surfactants, fertilizers and customaryadjuvants.
 8. The formulation as claimed in claim 7, wherein acombination of a herbicide and an oligo- or polymer is present togetherwith a safener and/or a growth regulator.
 9. The use of a combination asclaimed in claim 1 or of a formulation as claimed in claim 7 or 8 forsuppressing antagonistic interactions during the application of one ormore agrochemically active compounds for controlling harmful plants. 10.The use of a combination as claimed in claim 1 or of a formulation asclaimed in claim 8 or 9 for increasing crop selectivity during theapplication of one or more agrochemically active compounds forcontrolling harmful plants.
 11. A method for controlling harmfulorganisms, in particular harmful plants, which comprises applying in amanner known per se a combination as claimed in claim 1 or a formulationas claimed in claim 9 or
 10. 12. A process for preparing a combinationas claimed in claim 1 or a formulation as claimed in claim 8 or 9, whichcomprises combining the active compound by customary processes which areknown per se, preferably by dissolving, stirring or mixing, with asuitable polymer, and introducing this combination into the formulation,if appropriate with other active compounds, adjuvants and additives.